How Do You Charge For Sculpted Cakes

Right now I only decorate as gifts for family and friends, and charge for ingredients for co-workers. My question is, if you need to make 2 recipes for a shaped cake but end up cutting a fair amount away, do you charge for the total amount or just what they receive and how do you determine how many it will feed?TIAVAL

It will be interesting to hear the different pricing calculations people use for sculpted cakes. On the one hand, you need to charge for all ingredients used regardless of how much you cut away. On the other hand, charging by the serving does not take into account what you carved away, but it is usually covered by a higher price per serving for sculpted cakes.